Chrysanthemum plant named Lemon Tayrona

ABSTRACT

A Chrysanthemum plant named Lemon Tayrona particularly characterized by its flat capitulum form; decorative capitulum type; light lemon-yellow ray floret color, with a fresh green center of the flower; diameter across face of capitulum of 63 to 73 mm when fully opened, when grown as a single stem spray cut mum; photoperiodic flowering response to short days when grown in Salinas, Calif., is 52 to 57 days after start of short days; flowering response in Bogota, Colombia, under temperatures of minimum 7 degrees Celsium night and maximum 29 degrees Celsius day is 66 to 68 days; plant height is 74 to 79 cm when grown in Salinas with 7 to 10 long days prior to start of short days; height is 102 to 117 cm when grown in Bogota with 14 long days prior to start of short days; peduncle length of the first lateral at flowering after removing the apical bud without growth regulator applications is 10 cm when grown in Salinas, and 15 cm when grown in Bogota; peduncle length of the fourth lateral at flowering is 13 cm when grown in Salinas, and 20 to 23 cm when grown in Bogota; and excellent tolerance to low night temperatures for bud initiation and flower development.

The present invention comprises a new and distinct cultivar ofChrysanthemum, botanically known as Dendranthema grandiflora, andreferred to by the cultivar name Lemon Tayrona.

Lemon Tayrona, identified as 0804 (85-249G04), is a product of amutation induction program. The new cultivar was discovered and selectedby Cornelis P. VandenBerg on Sep. 4, 1990 as a reselection of anirradiation selection identified as 0614, which was selected on Nov. 13,1989 in a controlled environment in Salinas, Calif., as one floweringplant within a flowering block established as rooted cuttings from stockplants which had been exposed as unrooted cuttings to an X-ray source of1500 rads in Fort Myers, Fla., on May 11, 1989. The irradiated parentcultivar was the cultivar identified as Tayrona, disclosed in U.S. PlantPat. No. 7,482. Tayrona is described as a decorative spray cut mum witha flat capitulum form; a white ray floret color with a fresh greencenter of the flower; diameter across face of capitulum of 63 to 73 mmwhen fully opened; flowering response period of 50 to 57 days afterstart of short days in Salinas, Calif., and of 64 to 68 days in Bogota,Colombia; plant height of 74 to 86 cm when grown in Salinas with 6 to 11long days prior to start of short days, and of 97 to 119 cm when grownin Bogota with 14 to 15 long days prior to start of short days; andexcellent tolerance to low night temperatures for bud initiation andflower development. The above description of Tayrona has a wider rangeof measurements than the description of Tayrona in U.S. Plant Pat. No.7,482. This is based on the continued flowering trials of Tayrona afterpreparing the plant patent application for Tayrona. Tayrona wascommercially introduced in July 1990.

The irradiation program resulting in Lemon Tayrona had as its primaryobjective the expansion of color ranges of the parent cultivar Tayrona.The irradiation program comprised irradiating cuttings of the parentcultivar at irradiation levels of 1500, 1750 and 2000 rads. A total of1198 cuttings harvested from a total of 225 irradiated plants wereplanted on Sep. 11, 1989, Sep. 4, 1989 and Aug. 21, 1989 for plantsirradiated at 1500 rads, 1750 rads and 2000 rads, respectively. Ofthese, 16 initial selections were made, which selections were thenrevegetated and reflowered. Four consecutive flowerings resulted indiscarding 12 of the original 16 selections on Sep. 4, 1990. Three codes(plants) were reselected prior to discarding on the same date, whilefour codes were retained as PI (Possible Introduction) status. The fourretained codes and the three reselections were tested in Salinas,Calif., and in Bogota, Colombia, ultimately resulting in discarding fiveof these codes, and the decision to introduce one code 0584 as YellowTayrona, disclosed in pending application Ser. No. 07/919,257, and onereselected code 0804 as Lemon Tayrona.

The first act of asexual reproduction of Lemon Tayrona was accomplishedwhen vegetative cuttings were taken from the reselection in November1990 in a controlled environment in Salinas, Calif., by techniciansworking under supervision of Cornelis P. VandenBerg.

Horticultural examination of controlled flowerings of successiveplantings has shown that the unique combination of characteristics asherein disclosed for Lemon Tayrona are firmly fixed and are retainedthrough successive generations of asexual reproduction.

Lemon Tayrona has not been observed under all possible environmentalconditions. The phenotype may vary significantly with variations inenvironment such as temperature, light intensity and daylength, without,however, any variance in genotype.

The following observations, measurements and comparisons describe plantsgrown in Salinas, Calif., and in Bogota, Colombia, under greenhouseconditions which approximate those generally used in commercialgreenhouse practice. The low night temperature tolerance was determinedin repeated flowerings in Bogota, Colombia.

The following traits have been repeatedly observed and are determined tobe basic characteristics of Lemon Tayrona, which, in combination,distinguish this Chrysanthemum as a new and distinct cultivar:

1. Flat capitulum form.

2. Decorative capitulum type.

3. Light lemon-yellow ray floret color, with a fresh green center of theflower.

4. Diameter across face of capitulum of 63 to 73 mm when fully opened,when grown as a single stem spray cut mum.

5. Photoperiodic flowering response to short days when grown in Salinas,Calif., is 52 to 57 days after start of short days. Flowering responsein Bogota, Colombia, under temperatures of minimum 7 degrees Celsiusnight and maximum 29 degrees Celsius day is 66 to 68 days.

6. Plant height is 74 to 79 cm when grown in Salinas with 7 to 10 longdays prior to start or short days; height is 102 to 117 cm when grown inBogota with 14 long days prior to start of short days.

7. Peduncle length of the first lateral at flowering after removing theapical bud without growth regulator applications is 10 cm when grown inSalinas, and 15 cm when grown in Bogota. Peduncle length of the fourthlateral at flowering is 13 cm when grown in Salinas, and 20 to 23 cmwhen grown in Bogota.

8. Excellent tolerance to minimum low night temperatures of 7° C. forbud initiation and flower development.

The accompanying photographic drawing is a side view of single stem cutspray mum of Lemon Tayrona, with the colors being as nearly true aspossible with illustrations of this type.

Of the commercial cultivars known to the inventor, the most similar incomparison to Lemon Tayrona is the parent cultivar Tayrona. All traitsof Lemon Tayrona are similar to those of Tayrona, except for the rayfloret color, the flowering response and the plant height. Lemon Tayronahas a light lemon-yellow ray floret color, while Tayrona has a white rayfloret color. Both Lemon Tayrona and Tayrona have a fresh green centerof the flower. In several of our trials in Salinas Lemon Tayrona hasbeen slightly slower in flowering response by one to two days thanTayrona. In one trial in Salinas Lemon Tayrona was 5 cm taller thanTayrona. In a recent flowering in Bogota, Colombia, Lemon Tayrona wasone day slower in flowering response and 8 cm taller when compared withTayrona.

In the following description color references are made to The RoyalHorticultural Society Colour Chart. The color values were determined onplant material grown as a single stem spray cut mum in Salinas, Calif.on Dec. 27, 1991.

Classification:

Botanical.--Dendranthema grandiflora cv Lemon Tayrona.

Commercial.--Flat decorative cut spray mum.

INFLORESCENCE

A. Capitulum:

Form.--Flat.

Type.--Decorative.

Diameter across face.--63 to 73 mm when fully opened.

B. Corolla of ray florets:

Color (general tonality from a distance of three meters).--Lightlemon-yellow, with green center of flower.

Color (upper surface).--5B to 5D. Mid center overcast with 144A.

Color (under surface).--5C to 5D.

Shape.--Outer petals straight, inner petals slightly incurved; crosssection concave.

C. Corolla of disc florets:

Color (mature).--Closest to 14A.

Color (immature).--Closest to 144A.

D. Reproductive organs:

Androecium.--Present on disc florets only; scant pollen.

Gynoecium.--Present on both ray and disc florets.

PLANT

A. General appearance:

Height.--74 to 79 cm when grown in Salinas with 7 to 10 long days priorto start of short days; height is 102 to 117 cm when grown in Bogotawith 14 long days prior to start of short days.

B. Foliage:

Color (upper surface).--147A.

Color (under surface).--147B.

I claim:
 1. A new and distinct Chrysanthemum plant named Lemon Tayrona,as described and illustrated.